Bridge Repair on the Parlor Guitar

December 2017. I noticed the bridge had started to pull off the sound board on the Dirty Thirties parlor guitar.This happened a couple of times on my $50 Rogue guitar also. I document the repair on the parlor guitar below.

I heated up my old soldering iron. It is has a copper oval to serve as a small heating iron. I touched the heating iron to the bridge, moved it around slowly to evenly heat the bridge without letting it get too hot. I checked the bridge every few seconds with my hand to monitor the heating process.When it seemed warm enough, I slipped a thin taping knife under the bridge where it was pulling away from the sound board. I slid the knife until I heard a little creak from the sound board, then heated the bridge again with the iron. I continued to patiently heat the bridge and slide the knife until the bridge popped off:

The underside of the bridge has a layer of glue on it and there is glue on the sound board. I carefully scraped the glue off the sound board with a wood chisel:

I used my bench belt sander to remove the glue from the bridge. This picture shows the clean underside of the bridge. The trapezoid block to the left is the caul that will slip under the bridge plate when I clamp the bridge on later:

Here is the custom caul I made to make contact with the bridge in three places. The notch in the caul will permit the use of an aligning pin on the bass side. To insure correct location of the bridge, I used multiple layers of blue tape to make little tape borders against which I can push the bridge. I carefully measured using a long ruler to verify the correct location. I found the treble side of the bridge to be a little too close to the fingerboard, so I will move it back very slightly (scale length + 1/16" to the front of the saddle slot):

Glue applied:

December 9. Clamped, with drill bit as pin, good squeeze-out:

Tape pulled and glue wiped away with damp paper towels:

The next morning:

I should have taken a before picture. The bridge is sitting firmly on the soundboard now but success will be confirmed only after I restring, tune and play the guitar.

December 31, 2017. The guitar has been strung for about 20 days. The bridge is stable, no sign of movement: